Noninvasive positive pressure ventilation: Increasing use in acute care
ABSTRACTIn the past 2 decades, noninvasive positive pressure ventilation (NIPPV) has been increasingly used in acute respiratory failure to avoid the risks associated with intubation. It is now considered standard first-line therapy in several situations. In this review, we summarize how NIPPV has evolved, the current level of evidence that supports its use in various clinical situations, its potential contraindications, and its limitations in acute respiratory failure.
KEY POINTS
- The advantages of NIPPV over invasive ventilation are that it preserves normal physiologic functions such as coughing, swallowing, feeding, and speech and avoids the risks of tracheal and laryngeal injury and respiratory tract infections.
- The best level of evidence for the efficacy of NIPPV is in acute hypercarbic or hypoxemic respiratory failure during exacerbations of chronic obstructive pulmonary disease, in cardiogenic pulmonary edema, and in immunocompromised patients.
- NIPPV should not be applied indiscriminately for lessestablished indications (such as in unconscious patients, respiratory failure after extubation, acute lung injury, or acute respiratory distress syndrome), in severe hypoxemia or acidemia, or after failure to improve dyspnea or gas exchange. The use of NIPPV in these situations may delay a necessary intubation and increase the risks of such a delay, including death.
MISCELLANEOUS APPLICATIONS
The more widespread use of NIPPV has encouraged its use in other acute situations, including during procedures such as percutaneous endoscopic gastrostomy (PEG)57,58 or bronchoscopy,59,60 for palliative use in patients listed as “do-not-intubate,”61–63 and for oxygenation before intubation.64
NIPPV during PEG tube insertion
NIPPV during PEG tube placement is particularly useful for patients with neuromuscular diseases who are at a combined risk of aspiration, poor oral intake, and respiratory failure during procedures. The experience with patients with amyotrophic lateral sclerosis58 and Duchenne muscular dystrophy57 indicates that even patients at high risk of respiratory failure during procedures can be successfully managed with NIPPV. The most recent practice parameters for patients with amyotrophic lateral sclerosis propose that patients with dysphagia may be exposed to less risk if the PEG procedure is performed when the forced vital capacity is greater than 50% of predicted.65
In randomized trials of CPAP59 or pressure-support NIPPV60 in high-risk hypoxemic patients who needed diagnostic bronchoscopy, patients in the intervention groups fared better than those who received oxygen alone, with better oxygenation during and after the procedure and a lower risk of postprocedure respiratory failure. Improved hemodynamics with a lower mean heart rate and a stable mean arterial pressure were also reported in one of those studies.60
Palliative use in ‘do-not-intubate’ patients
In patients who decline intubation, NIPPV appears to be most effective in reversing acute respiratory failure and improving mortality rates in those with COPD or with cardiogenic pulmonary edema.61,62 Controversy surrounding the use of NIPPV in “do-not-intubate” patients, particularly as a potentially uncomfortable life support technique, has been addressed by a task force of the Society of Critical Care Medicine, which recommends that it be applied only after careful discussion of goals of care and parameters of treatment with patients and their families.63
Oxygenation before intubation
In a prospective randomized study of oxygenation before rapid-sequence intubation via either a nonrebreather bag-valve mask or NIPPV, the NIPPV group had a higher oxygen saturation rate before, during, and after the intubation procedure.64
Acknowledgment: The authors wish to thank Jodith Janes of the Cleveland Clinic Alumni Library for her help with reference citations and with locating articles.
